My periods used to come every 18th of every month but the last 2 months they have been late 1st time it was a week late second time it was 4daays late. When i come on im heavy for about 2 hours then go light for a couple days then spotting. When normally id come on really heavy for a few days then get lighter to nothing after the third day. Since the first late one i have been getting headaches on and off everyday. Feeling sick, but i havent thrown up yet. Light cramping in my pelvic area. Tiredness. Emotional, i cry over nothing when i dont normally cry at all. I go from happy to crying to hyper to angry in a matter of minutes. Im 18 and have a boyfriend who i have unprotected sex with almost every other day. I am on birth control pill to but due to late periods ive had to delay them untill ive finished my period. Please can someone give me a rough answer to this as i cant book in with my doctor as they always busy! Help please!